• Title/Summary/Keyword: 노쇠함

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Re-engineering framework for improving reusability of embedded software (임베디드 소프트웨어의 재사용성 향상을 위한 리엔지니어링 프레임워크)

  • Kim, Kang-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.4
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    • pp.1-9
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    • 2008
  • Most consumer electronics companies hold numerous line-ups to cope with divergent customer's needs. To cope with current situation, most products are derived from the 'base product' which is developed for brand new features with respect to the change requests. That is called derivation. After 'base code' is developed for newly introduced products, some modification will occur corresponding to the derivative product models. So, quality attributes of 'base code' affects quality and productivity of 'derived code'. But in the middle of continuous modification to 'base code', violation of architectural design decision and unauthorized or maybe unsophisticated change to source code willing to happen and thus it cause critical problem. Those code has 'aging symptom' both architectural and code level in nature. In this paper, we introduced reengineering framework which guide the procedure and tactics to find and fix 'aging symptom' for improvement on quality attribute of 'base code'.

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Roles of Fisetin on Skin Barrier Function and Anti-aging in Epidermal Keratinocyte (각질형성세포에서 Fisetin의 피부장벽 기능 개선 및 항노화 효능 검증)

  • Lee, Kyung-Ha;Kim, Wanil
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.4
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    • pp.391-401
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    • 2020
  • Flavonoids are polyphenolic compounds derived from plants metabolites and are known to be capable of controlling various human physiological functions. Among them, fisetin (3,3', 3', 7-tetrahydroxyflavone) is found in various fruits and vegetables, and it has been recently known to restore the function of certain tissues through senolytic activity. In this study, targeting human epidermal keratinocytes, control of skin barrier genes and antioxidant efficacy of fisetin were analyzed. Fisetin increased the activity of telomerase and decreased the expression of CDKN1B. In addition, it increased the expression of KRT1, FLG, IVL, and DSP, which are main genes that make up the skin barrier. The fisetin also increased the expression of CerS3 and CerS4 genes, which are forms of ceramide synthases. These results show that the efficacy of fisetin is not limited as senolytics but is also involved in various physiological regulation of human keratinocytes. Therefore, we consider that fisetin could be used as an active ingredient in cosmetics and pharmaceuticals.

Effects of Putrescine on Senescence in Detached Leaves of Chinese Cabbage in the Light (광조건에서 Putrescine이 잘라낸 배추잎의 노쇠과정에 미치는 효과)

  • 조형택
    • Journal of Plant Biology
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    • v.31 no.3
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    • pp.227-237
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    • 1988
  • Effects of putrescine on senescence in detached leaves of Chinese cabbage (Brassica campestris L.) in the light were investigated. The putrescine as a potent antisenescence substane markedly inhibited chlorophyll and protein loss at the 10mM concentraton in the detached leaves during the dark incubation. In the light, however, putrescine showed the opposite effects to dark incubation. The chlorphyll loss by putrescine in the light was stopped with darktransfer, and inhibited competitively by a divalent cation Ca2+. In the light, putrescine reduced the protease activity. Putrescine, in the light, increased H2O2 content and reduced the activities of enzymes -superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6-involved in inhibiting the accumulation of free radicals. These results suggest that the effects of puterscine on chlorophyll and protein loss in detached leaves of Chinese cabbage in the light are related to the cationic nature of putrescine and the accumulation of free radicals.

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Lateral Electric Field Model and Degradation Mechanism of surface-Channel PMOSFET's (SC PMOSFET의 수평 전개 모델과 노쇠화 메카니즘)

  • 양광선;박종태;김봉렬
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.1
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    • pp.54-60
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    • 1994
  • In this paper, we present the analytical models for the change of the lateral electric field distribution and the velocity saturation region length with the electron trapping of stressed SC-PMOSFET in the saturation region. To derive the hot-electron-induced lateral electric field of stressed SC-PMOSFET. Ko's pseudo two dimensional box model in the saturation region which illustrates the analysis of the velocity saturation region is modified under the condition of electron trapping in the oxide near the drain region. From the results, we have the following lateral electric field in the y-direction, that is, E(y) ES1satT.cosh(y/l) qNS1tT.sinh(y/l)/lCox. It is shown that the trapped electrons influence the field in the drain region. decreasing the lateral electric field. Calculated velocity saturaion length increases with the trapped electrons. increasing the drain current of stressed SCPMOSFET. This results well explain the HEIP phenomenon of PMOSFET's.

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특집 - 감추지 말고 웃으면서 치료하라!

  • Choe, Hyeong-Gi
    • The Monthly Diabetes
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    • s.209
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    • pp.19-24
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    • 2007
  • 당뇨병에 성기능장애가 많다는 것은 옛날부터 알려져 있지만 실제로는 그릇된 지식과 선입관에 의해 과장되게 잘못알고 있는 경우가 많다. 당뇨병이라고 모두 발기부전 환자는 아닌 것이며 정상 건강인보다 조금 높은 빈도를 보이는 것뿐이다. 식사요법과 운동요법으로 혈당조절을 잘하고 합병증을 예방하면 정상인과 다름없는 성생활을 할 수 있으며 인슐린 치료를 계속하면서 주의 깊게 혈당을 조절하고 합병증을 예방하면 60세 이후까지도 정상적인 성생활이 가능하다. 정상인도 노쇠하면 자연현상으로 언젠가는 모두 발기부전이 되므로 당뇨병환자만이 발기부전이 오는 것은 아니므로 미리 겁내고 불안해할 필요는 없는 것이다. 당뇨병환자중에는 선입관에 의해 당뇨라는 진단을 받고 정신적 충격과 그릇된 지식으로 심인성 발기부전에 빠지는 사람이 상당히 많다. 그러므로 당뇨병환자는 정상인보다 더 많은 노력을 하며 합병증의 병발을 미연에 방지하는 것이 가장 중요하다.

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Hot-Carrier-Induced Degradation in Submicron MOS Transistors (Submicron MOS 트랜지스터의 뜨거운 운반자에 의한 노쇠현상)

  • 최병진;강광남
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.7
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    • pp.780-790
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    • 1988
  • We have studied the hot-carrier-induced degradation caused by the high channel electric field due to the decrease of the gate length of MOSFET used in VLSI. Under DC stress, the condition in which maximum substrate current occures gave the worst degradation. Under AC dynamic stress, other conditions, the pulse shape and the falling rate, gave enormous effects on the degradation phenomena, especially at 77K. Threshold voltage, transconductance, channel conductance and gate current were measured and compared under various stress conditions. The threshold voltage was almost completely recovered by hot-injection stress as a reverse-stress. But, the transconductance was rapidly degraded under hot-hole injection and recovered by sequential hot-electron stress. The Si-SiO2 interface state density was analyzed by a charge pumping technique and the charge pumping current showed the same trend as the threshold voltage shift in degradation process.

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The Characteristics of Degraded Drain Output Resistance of NMOSFET due to Hot Electron Effects (Hot electron 효과로 노쇠화된 NMOSFET의 드레인 출력저항 특성)

  • 김미란;박종태
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.9
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    • pp.38-45
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    • 1993
  • In this study, the degradation characteristics of drain output resis-tance was described due to hot electron effects. An semi-empirical model for the degraded drain output resistance was derived from the measured device characteristics. The suggested model was verified from the measured data and the device parameter dependence was also analyzed. The degradation of drain output resistance was increased with stress time and had linear relationship with the degradation of drain current. The device lifetime which was defined by failure criteria of drain output resistance (such as $\Delta$ro/roo=5%) was equivalent to that of failure criteria of drain current (such as $\Delta$ID/ID=5%)

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Effects of Spermidine on the Senescence in Leaf Discs of Chinese Cabbage (Spermidine이 배추 잎 원형절편의 노쇠과정에 미치는 효과)

  • 신정림
    • Journal of Plant Biology
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    • v.31 no.2
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    • pp.155-164
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    • 1988
  • The rapid senescence of detached Chinese cabbage leaf discs in darkness is first manifested by a sharp rise in malondialdehyde content (indicated by distruption of membrane structure), then by a rise in peroxidase activity and a decrease in catalase activity, and ultimately by chlorophyll degradation. These changes in parameters besides the catalase activity during senescence were delayed by application of spermidine. Especially, 10-4M spermidine almost completely arrested chlorophyll degradation after incubaton over 5 days. Spermidine reduced the amount of ethylene produced by senescing leaf discs. Additionally, it also reduced IAA-induced ethylene production. Calcium ion (1mM, 10mM) supplied together with the spermidine diminished the spermidine action, indicating probable involvement of an initial ionic attachment mechanism. These results suggest that spermidine can be used as an anti-senescence agent for plants and that this agent may stabilize membrane structure through interaction with the negatively charged loci on the membrane and exert the influence during senescence.

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Hot carrier effects and device degradation in deep submicrometer PMOSFET (Deep submicrometer PMOSFET의 hot carrier 현상과 소자 노쇠화)

  • 장성준;김용택;유종근;박종태;박병국;이종덕
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.4
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    • pp.129-135
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    • 1996
  • In this paper, the hot carrier effect and device degradation of deep submicrometer SC-PMOSFETs have been measured and characterized. It has been shown that the substrate current of a 0.15$\mu$m PMOSFET increases with increasing of impact ionization rate, and the impact ionization rate is a function of the gate length and gate bias voltage. Correlation between gate current and substrate current is investigated within the general framework of the lucky-electron. It is found that the impact ionization rate increases, but the device degradation is not serious with decreasing effective channel length. SCIHE is suggested as the possible phusical mechanism for enhanced impact ionization rate and gate current reduction. Considering the hot carrier induced device degradation, it has been found that the maximum supply voltage is about -2.6V for 0.15$\mu$m PMOSFET.

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The Threshold Voltage and the Effective Channel Length Modeling of Degraded PMOSFET due to Hot Electron (Hot electron에 의하여 노쇠화된 PMOSFET의 문턱전압과 유효 채널길이 모델링)

  • 홍성택;박종태
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.8
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    • pp.72-79
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    • 1994
  • In this paper semi empirical models are presented for the hot electron induced threshold voltage shift(${\Delta}V_{t}$) and effective channel shortening length (${\Delta}L_{H}$) in degraded PMOSFET. Trapped electron charges in gate oxide are calculated from the well known gate current model and ΔLS1HT is calculated by using trapped electron charges. (${\Delta}L_{H}$) is a function of gate stress voltage such as threshold voltage shift and degradation of drain current. From the correlation between (${\Delta}L_{H}$) has a logarithmic function of stress time. From the measured results, (${\Delta}V_{t}$) and (${\Delta}L_{H}$) are function of initial gate current and device channel length.

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